Image processing method and image input device, control device, image output device and image processing system employing same

ABSTRACT

To reliably and simply prevent the output of specified image data, a unit to detect a pattern is installed in one of the devices in a system consisting of an image scanner  1 , control device  2  (a personal computer) and printer  3  which are connected consecutively. This pattern detection unit contains a unit which detects a specified pattern from the mass of image data representing a document. Once this pattern has been found, either the subsequent image data are altered before being output or output of the image data is interrupted. When the system starts up, the control unit for each device checks whether that device, or one of the other devices in the system, has a pattern detection unit as described above. If it determines that no device has such a unit, it halts operation.

FIELD OF THE INVENTION

[0001] The invention relates to an image processing method by whichimage data representing a 2-dimensional object are input and subjectedto specified processing, and the processed image data are output. Theinvention also relates to an image input device, a control device, animage output device and an image processing system in which this methodis employed.

BACKGROUND OF THE INVENTION

[0002] In recent years, copy machines have been developed which can reada document, such as a color photograph, and generate a high-quality copyin which the colors are accurately reproduced. Such copy machines arenow used for a wide variety of applications.

[0003] However, the resolution of these copy machines is high enoughthat someone might think it worthwhile to try to run off multiple copiesof bank notes, stock certificates, or other documents which may not belegally reproduced. To prevent such one-touch counterfeiting, it hasbeen suggested (Patent Publication 2-210481) that copy machines shouldbe given the capability of recognizing a characteristic pattern onnon-reproducible documents so that copies of such documents will not beoutput.

[0004]FIG. 28 shows the general configuration of a device to provide thecapability to prevent copying described above. It consists primarily ofimage generation unit 50, control unit 51, image formation unit 52 andpattern detection unit 53.

[0005] The aforesaid image generation unit 50 consists of an imagescanner which reads the document and generates red (R), blue (B) andgreen (G) image data. Control unit 51 inputs these image data andconverts them to yellow (Y), magenta (M), cyan (C) and black (K) imagedata which can be used in image formation unit 52. Image formation unit52 accepts the converted image data and transcribes them.

[0006] Pattern detection unit 53 determines whether the image datagenerated by image generation unit 50 contain the characteristic patternwhich identifies a non-reproducible document. The result of thisdetermination is output to control unit 51. When control unit 51receives from unit 53 the result that the characteristic pattern hasbeen found, it outputs a control signal (shown in the drawing by dottedlines) to image formation unit 52 or image generation unit 50 to ceaseoperating. With this method, the generation or output of image dataidentified by the characteristic pattern will be interrupted, and thecopying operation will be halted or the entire surface of the copy whichis output will be covered with a particular color.

[0007] Recently, printers have been developed which are capable ofoutputting highly accurate color images. Now anyone with an imagescanner, a personal computer and a printer can easily make reproductionsof color documents which are as accurate as those of high-resolutioncopy machines. For this reason a demand has sprung up for a device whichcould be installed in such a system to prevent the reproduction ofspecified image data and thereby prevent the system from being used forunlawful copying.

SUMMARY OF THE INVENTION

[0008] The present invention addresses the problems discussed above. Oneobjective is to provide a device which would be able to recognize acharacteristic pattern in a document's image data and control the outputof image data based on the result of this recognition. This would be asimple and reliable way to prevent the output of specified image data.

[0009] Another objective of this invention is to provide a device ableto determine whether there is a means either in the system or connectedto it which could detect specific image data as described above andcontrol the output of image data. If it is determined that there is nosuch device, it would partially or completely halt the function of thesystem so that output of the specific image data would be completelyarrested.

[0010] In one embodiment of the present invention, the image data to beprocessed are color image data consisting of the combination of imagedata associated with a number of color signals which are inputsuccessively.

[0011] In another embodiment of the present invention, the specifiedpattern is detected as follows. For each color signal, all image dataexcept those which will be input last are stored separately. When thefinal data are input, an image created by combining these data with allthe aforesaid image data which have been stored is compared with areference pattern.

[0012] In still another embodiment of the present invention, the methodis implemented by a device which detects a specified pattern. Thisdevice consists of: a device to store separately all image data for eachcolor signal except those data which are to be input last; a device tocompare with a reference pattern an image created by combining, when thelast image data have been input, the final input data with all the imagedata stored in the aforesaid storage device; and a device to determine,based on the result of the comparison performed by the aforesaidcomparison device, whether the aforesaid specified pattern can be foundin the image data being processed.

[0013] In another embodiment of the present invention, the image datafor the different color signals are successively compared with areference image. The result of the comparison for each color signal isstored, and the results of all the comparisons are cumulated to detectthe specified pattern.

[0014] In another embodiment, the aforesaid means of detecting aspecified pattern consists of: a device to compare the image data foreach color signal to a specified reference pattern; a device to storefor each color signal the result of the comparison performed by theaforesaid comparison device; and a device to cumulate the results of thecomparisons for the different color signals which are stored in theaforesaid storage device and determine whether the aforesaid specifiedpattern can be found in the image data being processed.

[0015] In one embodiment of the present invention, an image processingmethod is employed by which image data representing a 2-dimensionalobject are input and subjected to specified processing, and theprocessed image data are output. When it becomes clear at some pointduring the aforesaid processing that either the processing to determinewhether a specified pattern can be found in the image data or theprocessing to control the output of image data according to the resultof the determination will not be executed, the image processing functionis partially or completely halted.

[0016] Another embodiment of the present invention is a system toimplement the processing method described above, consisting of: a devicewhich detects whether the system has a means to determine whether aspecified pattern can be found in the image data being processed; adevice which detects whether the system has a means to control theoutput of image data based on the result of the determination made bythe aforesaid means of detecting a specified pattern; and a device whichhalts the function of the system either partially or completely when thefirst of the aforesaid detection devices detects that the system has nomeans to determine whether a specified pattern can be found in the imagedata being processed, or when the second of the aforesaid detectiondevices detects that the system has no means to control its output.

[0017] Other embodiments concern devices used to input image datarepresenting a 2-dimensional object. These input devices have a means todetermine whether a specified pattern can be found in the image databeing processed and a means to control the output of image data based onthe result of the determination made by the means of detecting aspecified pattern. The image data which are to be processed are colorimage data consisting of the combination of image data associated with anumber of color signals which are input successively.

[0018] In one embodiment, the aforesaid means of detecting a specifiedpattern consists of: a device to store separately all image data foreach color signal except those data which are to be input last; a deviceto compare with a reference pattern an image created by combining, whenthe last image data have been input, the final input data with all theimage data stored in the aforesaid storage device; and a device todetermine, based on the result of the comparison performed by theaforesaid comparison device, whether the aforesaid specified pattern canbe found in the image data being processed.

[0019] In another embodiment, the aforesaid means of detecting aspecified pattern consists of: a device to compare the image data foreach color signal to a specified reference pattern; a device to storefor each color signal the result of the comparison performed by theaforesaid comparison device; and a device to cumulate the results of thecomparisons for the different color signals which are stored in theaforesaid storage device and determine whether the aforesaid specifiedpattern can be found in the image data being processed.

[0020] In still another embodiment, an image input device identical tothat described above has, either integral to itself or in a deviceconnected to it, a means to determine whether the system has a devicewhich detects a specified pattern in the image data being processed anda device which controls data output based on the result of the detectionmade by the device to detect a specified pattern; and a means to haltthe function of the device either partially or completely when theaforesaid determination device has determined that the system lackseither the aforesaid device to detect a pattern or the device to controlthe output.

[0021] Other embodiments concern a control device which executesspecified processing on image data representing a 2-dimensional objector a device to output image data representing a 2-dimensional object.

[0022] In other embodiments of the present invention, an image createdby combining the input data with image data entered previously andstored is compared with a reference pattern when the final image dataare input. In this way it can be determined whether the image containsthe specified pattern. This method makes it possible to execute patterndetection processing on an image created by successively combining imagedata for multiple color signals.

[0023] In some embodiments, the image data for the each color signal arecompared with a reference image at the time they are generated. Theresult of the comparison for each color signal is stored, and theresults of all the comparisons are cumulated to determine whether thedata contain the specified pattern. This method makes it possible toexecute pattern detection processing on a color image created bysuccessively combining image data for multiple color signals.

[0024] Finally, in some embodiments of the present invention, when thefunction of detecting the pattern or the function of controlling theoutput of image data are not present, the function of the system ispartially or completely halted. Thus, if someone should substitute someother device for the device which detects a pattern or controls theoutput, the function of that other device will be halted and it willbecome impossible to output image data for the document.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025]FIG. 1 illustrates the configuration of an image processing systemdesigned according to this invention.

[0026]FIG. 2 is a block diagram of an image scanner in which a patterndetection unit has been installed.

[0027]FIG. 3 is a block diagram of the pattern detection unit.

[0028]FIG. 4 illustrates how the color image data are generated.

[0029]FIG. 5 shows an example of a document which may not lawfully becopied.

[0030]FIG. 6 illustrates the method used to search for the pattern ofthe mark.

[0031]FIG. 7 shows examples of image data which are output when thepattern detection unit shown in FIG. 3 is used.

[0032]FIG. 8 is a block diagram of another pattern detection unit.

[0033]FIG. 9 shows another method to generate color image data.

[0034]FIG. 10 is a block diagram of another pattern detection unit.

[0035]FIG. 11 is a block diagram of another pattern detection unit.

[0036]FIG. 12 is another example of a document which may not lawfully becopied.

[0037]FIG. 13 is a block diagram of a control device in which a patterndetection unit is installed.

[0038]FIG. 14 is a block diagram of a control device in which a patterndetection unit is installed.

[0039]FIG. 15 is a block diagram of a control device in which a patterndetection unit is installed.

[0040]FIG. 16 is a block diagram of a control device in which a patterndetection unit is installed.

[0041]FIG. 17 is a block diagram of a printer in which a patterndetection unit is installed.

[0042]FIG. 18 is a block diagram of a printer in which a patterndetection unit is installed.

[0043]FIG. 19 is a block diagram of a printer in which a patterndetection unit is installed.

[0044]FIG. 20 gives an example of the final output of the printer.

[0045]FIG. 21 gives an example of the final output of the printer.

[0046]FIG. 22 gives an example of the final output of the printer.

[0047]FIG. 23 gives an example of the final output of the printer.

[0048]FIG. 24 gives an example of the final output of the printer.

[0049]FIG. 25 gives an example of the final output of the printer.

[0050]FIG. 26 gives an example of the final output of the printer.

[0051]FIG. 27 is a flow chart of the processing executed by the controlunit for each device when the system starts up.

[0052]FIG. 28 is a block diagram of a dedicated copying device.

DETAILED DESCRIPTION OF THE INVENTION

[0053]FIG. 1 illustrates an image processing system which is an idealembodiment of this invention.

[0054] This image processing system consists of image scanner 1, controldevice 2, a personal computer, and printer 3, all of which are connectedtogether by an SCSI bus or a LAN circuit.

[0055] Image scanner 1 can generate image data in three primary colors.The R, G and B data which are generated are output in order to controldevice 2. Control device 2 inputs these image data into its internalinput unit, and outputs to printer 3 either RGB or YMCG image data,depending on which method it uses. The control unit in printer 3 drivesthe printing head or other print processing unit according to the imagedata it receives and copies an image of the document.

[0056] To prevent the copying of documents which have a specified markon them, this image processing system has, in either the aforesaidscanner 1, control device 2 or printer 3, a unit which determineswhether the image data being processed contain the shape of theaforesaid mark and which prevents the output of these image data to thenext stage (hereafter referred to as “the image detection unit”).

[0057] This detection unit is formed on a single chip. Building thischip into an existing circuit in a device will give that device thecapability of detecting the aforesaid mark.

[0058] If the detection unit is installed in image scanner 1, a patterndetection device R₁ to detect pattern must be placed between image datageneration device 4 and image data output device 5, as shown in FIG. 2.Detection device R₁, determines whether the specified pattern can befound in the image of the document generated by image data generationdevice 4. If it can, the image data are converted to a specified patternand output to data output device 5.

[0059]FIG. 3 shows the configuration of pattern detection device R₁.

[0060] In this embodiment, the RGB image data for each pixel of an imageconsisting of n number of pixels P₀ through P_(n-1) (shown in FIG. 4(1)) are input successively by image data generation device 4. If a markM₁ as shown in FIG. 5 is found in these image data, the document will betreated as non-reproducible.

[0061] The aforesaid detection device R₁ contains line memories 6 _(R),6 _(G) and 6 _(B), which store the image data for each color signal;image alteration unit 7; pattern detection unit PT₁; and selector 8.

[0062] Each of line memories 6 _(R), 6 _(G) and 6 _(B) has a bufferwhich corresponds to the size of the specified pattern M₁. The RGB imagedata for each pixel are transmitted by way of line memories 6 _(R), 6_(G) and 6 _(B) to image alteration unit 7 and selector 8.

[0063] Image alteration unit 7 alters the image data it receives bypainting over them in a specified pattern. Selector 8 selects either theoriginal image data from line memories 6 _(R), 6 _(G) and 6 _(B) or thealtered image data and outputs them to image data output device 5.

[0064] Detection unit PT₁ comprises primarily of pattern search unit 9;pattern extraction unit 10; line memories 11 _(R), 11 _(G) and 11 _(B);pattern matching unit 12; and reference memory 13. The image data foreach color signal transmitted by image data generation device 4 areinput into search unit 9 and line memories 11 _(R), 11 _(G) and 11 _(B)in synchronization with their input into the line memories 6 _(R), 6_(G) and 6 _(B).

[0065] Pattern search unit 9 extracts from the image data which havebeen input the pattern corresponding to the upper arc of the circle inthe mark. As can be seen in FIG. 6, pattern search unit 9 uses the arcpattern cp which it has extracted to calculate the coordinates of thecenter point 0 of the entire pattern. It outputs these coordinates topattern extraction unit 10.

[0066] Like the first set of line memories 6 _(R), 6 _(G) and 6 _(B),line memories 11 _(R), 11 _(G) and 11 _(B) correspond to the size ofmark M₁. Based on the coordinates of the center point 0, patternextraction unit 10 specifies the pixels in each of line memories 11_(R), 11 _(G) and 11 _(B) which correspond to the pattern of mark M andextracts the image data of each color signal which belong to thatpattern. Pattern matching unit 12 calculates the correlation between theextracted pattern and a reference pattern for mark M₁, which ispreviously stored in reference memory 13. It outputs the goodness of fitwhich is the result of this calculation to selector 8.

[0067] Ordinarily, selector 8 selects the original image data output byline memories 6 _(R), 6 _(G) and 6 _(B) and outputs them to image dataoutput device 5. When matching unit 12 inputs a goodness of fit whichexceeds a specified threshold value, selector 8 substitutes the alteredimage data from image alteration unit 7.

[0068] The alteration processing executed by image alteration unit 7 isnot limited to painting over the image data in a specified way. Unit 7might as an alternative gradually decrease the density value of theimage data which are being input.

[0069] With the processing described above, as shown in FIGS. 7 (1) and(2), all of the image beyond mark M₁, regardless of whether the image isbeing scanned from top to bottom or bottom to top, is painted overbefore it is output. If control device 2 synthesizes the results ofscanning the document from both directions, as shown in FIG. 7 (3), theportion of the image where mark M₁ is located will still not bereproduced.

[0070] If line memory 6 is provided with a buffer corresponding to thesize of the entire image, the image data for the entire document can bealtered before they are output.

[0071]FIG. 8 shows another ideal embodiment of pattern detection deviceR₁.

[0072] In this embodiment, the image data for three primary colorsignals generated by image data generation device 4 are inputsuccessively as portions of the frame (shown in FIG. 9). Patterndetection unit PT₂ has the same configuration as detection unit PT₁ inFIG. 3, to which has been added switching unit 14 and line memories 15_(R) and 15 _(G).

[0073] Pattern detection device R₁ inputs the image data for all threecolor signals frame unit by frame unit. This being the case, common linememories 6 and 11 store all three colors for image output and patterndetection.

[0074] The image memories 15 _(R) and 15 _(G) store one frame's worth ofimage data for each of R and G: R₀ through R_(n-1) and G₀ throughG_(n-1). When these image data are input, switching unit 14 switchestheir destination between image memories 15 _(R) and 15 _(G).

[0075] When the B image data, B₀ through B_(n-1), are input, switchingunit 14 switches their destination between search unit 9 and line memory11. Pattern search unit 9 combines the B data which are input with the Rand G data stored in the aforesaid image memories 15 _(R) and 15 _(G).Executing the same processing as is described above, it extracts thecenter point of the pattern corresponding to mark M₁ and outputs thesecoordinates to pattern extraction unit 10.

[0076] Based on the coordinates it receives from pattern search unit 9,pattern extraction unit 10 reads out of line memory 11 and imagememories 15 _(R) and 15 _(G) the RGB image data representing the patternof mark M₁. Matching unit 12 calculates the correlation between thepattern formed by the data which are read out and a reference pattern.It outputs the goodness of fit which is the result of this calculationto selector 8.

[0077] The image data generated by image data generation device 4 areinput successively into line memory 6. The original image data in linememory 6 which are associated with image data R₀ through R_(n-1) and G₀through G_(n-1) are output successively by way of selector 8 and imagedata output device 5 to control unit 2.

[0078] When the final B image data are input, as discussed earlier,pattern detection unit PT₂ executes the processing to detect the patternof mark M₁. When the resulting goodness of fit which is input bymatching unit 12 into selector 8 exceeds a specified threshold value,selector 8 switches the output designation to the data altered by imagealteration unit 7.

[0079] With this processing, once the pattern of mark M₁ is detected,the B image data input into control device 2 are reconformed into aspecified pattern. Even if control device 2 combines these B data withthe previously input R and G data, it will not be possible to reproducean image of the document.

[0080]FIG. 10 shows another ideal embodiment of pattern detection deviceR₁.

[0081] This embodiment executes the same processing as the device shownin FIG. 8 above. However, as the stage prior to switching unit 14,pattern detection unit PT₃ has a preprocessor unit 16, which reduces thevolume of data by thinning out or binarizing the image data. In place ofthe aforesaid image memories 15 _(R) and 15 _(G), PT₃ has image memories15 _(R)′ and 15 _(G)′, which store the image data which have beenprocessed by preprocessor unit 16.

[0082] Since the other components of PT₃ are identical to those shown inFIG. 8, they are not described again.

[0083]FIG. 11 shows another ideal embodiment of pattern detection deviceR₁.

[0084] This embodiment is also designed to handle image data input byimage data generation device 4 according to the method shown in FIG. 9above. Pattern detection unit PT₄ has the same pattern search unit 9,pattern extraction unit 10, line memory 11 and pattern matching unit 12as described above. It has three reference memories, 16 _(R), 16 _(G)and 16 _(B), which store reference patterns for the three color signals,a storage unit 17 for goodness of fit and a pattern detection unit 18.

[0085] Image data for the three primary colors are input successivelyinto pattern search unit 9 and line memory 11. The patterns representingmark M₁ in each color signals are extracted and matched against eachcolor signal of a reference pattern, and the goodness of fit iscalculated. The goodness of fit which have been calculated are stored instorage unit 17. When the B data have been input and the final matchingprocess is completed, pattern detection unit 18 reads out all threegoodness of fit values from storage unit 17 and makes an overalldetermination, the result of which it outputs to selector 8.

[0086] Just as in the embodiments pictured in FIGS. 8 and 10, selector 8selects from line memory 6 the original image data for R and G andoutputs them. If, when the B data are input, a determination is input tothe selector unit 8 that the pattern representing mark M₁ has beenfound, selector 8 switches the output designation to the data altered byimage alteration unit 7.

[0087] With the configuration described above, if mark M₁ can bespecified by a given color signal (red), the determination made when theimage data for that signal (in this case, the R data) have been inputcan also be used to cause selector 8 to switch the output data.

[0088] We shall next discuss two embodiments in which the patterndetection unit is built into control device 2.

[0089] In the following embodiments, we assume that the non-reproducibledocument has a mark M₂ like that shown in FIG. 12.

[0090]FIGS. 13 and 14 show embodiments in which detection device R₂ isplaced on the route leading to image input unit 20 in control device 2.The pattern detection unit PT in these embodiments has the sameconfiguration as one of units PT₁ through PT₄, depending on what methodimage scanner 1 uses to output its image data.

[0091] In FIG. 13, if the specified pattern is found in the image datainput from image data output device 5 of image scanner 1, the image datasent to input unit 20 will be altered. Pattern detection device R₂ hasan image alteration unit 7 and a selector 8 in addition to detectionunit PT.

[0092] The image data from image scanner 1 are input simultaneously intopattern detection unit PT, image alteration unit 7 and selector 8.Detection unit PT determines, using any of the embodiments describedabove, whether image data input by the scanner 1 contain the specifiedpattern. The result of this determination is output to selector 8.Depending on the result of the determination, selector 8 selects eitherthe original image data or the data altered by image alteration unit 7and outputs them to image input unit 20.

[0093]FIG. 14 shows an embodiment in which pattern detection device R₃halts the intake of image data by image scanner 1. In this case patterndetection device R₃ consists of input path L, along which the originalimage data from image scanner 1 are input to image input unit 20, andpattern detection unit PT. The result of the detection by unit PT isoutput to image input unit 20 and scanner control unit 19.

[0094] When pattern detection unit PT outputs the result that the imagedata input from image scanner 1 contain the specified pattern, scannercontrol unit 19 outputs to the intake portion of image scanner 1 acontrol signal to halt intake. At the same time, image input unit 20executes processing to invalidate the image data which have been readand communicates to a control unit, not pictured, the fact that there isa defect in the reading of the image data.

[0095] In both the above embodiments, the pattern detection unit isinserted on the path along which the image data from image scanner 1 areinput. However, it would also be possible to install the detection uniton the path along which the image data are output to printer 3.

[0096]FIG. 15 has a pattern detection unit identical to that in FIG. 13installed on the output path to printer 3. When the specified pattern isfound in the image data to be output, the image data are altered beforebeing output to printer 3. In this case, pattern detection device R₂inputs and processes either the RGB image data or the YMCK image dataconverted by image data converting unit 22, depending on theconfiguration of the printer 3 to which it is connected.

[0097]FIG. 16 has a pattern detection unit identical to that shown inFIG. 14 installed on the output path to printer 3. The result of thedetermination made by pattern detection unit PT is fed back to printercontrol unit 21. In this case, when pattern detection unit PT determinesthat the image data to be output contain the specified pattern, printercontrol unit 21 outputs a halt signal to the printer 3, and the printoperation is terminated.

[0098] We shall next discuss several embodiments in which the patterndetection unit is installed in printer 3.

[0099] The printer 3 shown in FIG. 17 inputs the YMCK image data fromcontrol device 2 into print control unit 24 by way of interface circuit23. Print control unit 24 transmits the image data to print processingunit 25, and controls the print operation of print processing unit 25from start to finish. A pattern detection device R₂, identical to thatin FIG. 13 or 15, is installed on the path along which image data areoutput from print control unit 24 to print processing unit 25.

[0100] In FIG. 18, a pattern detection device R₃, identical to that inFIG. 14 or 16 above, is installed on the path along which image data areoutput from print control unit 24 to print processing unit 25. Theresult of the determination made by detection unit PT is fed back toprint control unit 24. In this case, when detection unit PT determinesthat the image data to be output contain the specified pattern, printcontrol unit 24 outputs a halt signal to print processing unit 25, andthe print operation is interrupted.

[0101]FIG. 19 shows another example of how the pattern detection unitcan be incorporated in the design. The printer in this embodiment isconfigured so that the image data from interface circuit 23 are inputinto print processing unit 25 by way of buffer 26. A pattern detectiondevice R₃, identical to that in FIG. 18, is placed between interfacecircuit 23 and buffer 26. Output adjustment unit 27 is placed betweenprint control unit 24 and print processing unit 25.

[0102] The image data from interface circuit 23 are input simultaneouslyinto buffer 26 and pattern detection unit PT. Detection unit PT uses thesame method described above to determine whether the image data containthe specified pattern. The result of this determination is output toprint control unit 24 and output adjustment unit 27.

[0103] Ordinarily, the output adjustment unit 27 outputs the image datait receives through buffer 26 to print control unit 25 without furthertreatment, in response to a control signal from print control unit 24.However, when it receives a determination from the pattern detectionunit that the image data to be output contain the specified pattern, italters the image data from buffer 26. When print control unit 24receives the same determination result, it outputs a control signal tooutput adjustment unit 27 to cease its operation. The operation of printprocessing unit 25 is immediately halted.

[0104]FIGS. 20 through 24 give five examples of the copy which is outputby printer 3 in the embodiments which employ the aforesaid patterndetection device R₂ (FIGS. 13, 15 and 17).

[0105]FIG. 20 shows a case in which the image data beyond the pointwhere mark M₂ is detected have been transformed into a specifiedpattern. Every part of the document which is output beyond mark M₂ iscovered over with this pattern. In FIG. 21, the image data are alteredto gradually decrease the density of the portion of the image beyondmark M₂. The image in the copy gradually gets lighter until itdisappears.

[0106]FIGS. 22 through 24 give examples in which printer control unit 21in control device 2 or print control unit 24 in printer 3 supplementsthe altered data with additional image data before the copy is output.In the example shown in FIG. 22, the margin of the document has alsobeen printed with a cover pattern. In the example in FIG. 23, aspecified warning has been printed over the covered portion of theimage. In the example in FIG. 24, the print in the image gradually getslighter just as in FIG. 21, and a warning is printed in the margin.

[0107]FIG. 25 is an example of a copy output by an embodiment with theaforesaid detection device R₃ (FIGS. 14, 16, 18 and 19). The printing ofthe image is interrupted when mark M₂ is discovered, and the rest of thedocument remains blank.

[0108] In this case, too, as is shown in FIG. 26, a warning may beprinted in a specified location on the copy.

[0109] Like device R₁, the aforesaid pattern detection devices R₂ and R₃have line memories corresponding to the size of mark M₂. If the imagedata are delayed in these line memories before being output, the outputof the image data containing mark M₂ can be controlled.

[0110] In the image processing systems described above, devices R₁through R₃, which have a specified circuit pattern, are built intoexisting circuitry in one of the system devices. This designsignificantly reduces the labor and cost required to develop a system.If the user is free to store any desired reference pattern in thereference memory in detection unit PT, he can freely designate or changethe document to be prohibited.

[0111] This image processing system consists of three general purposedevices, image scanner 1, control device 2 and printer 3, which areconnected together. It would be easy, then, to disable the system byremoving the device (for example, the image scanner) with the detectionunit and substituting another device without such a unit.

[0112] To address this problem, the image processing system has thecontrol unit for every device in the system verify, at the time thesystem starts up, that the device or some other system device has apattern detection unit. If a control unit recognizes that there is nodetection unit, it orders that the operation of the device be halted.

[0113]FIG. 27 shows the control operation executed by the control unitfor each device when the system starts up.

[0114] Every control unit checks in Step 1 whether its device has apattern detection unit. If the answer is “no”, it checks in Step 2whether any other device has a detection unit.

[0115] If the devices are connected by an SCSI bus, they can be checkedsuccessively in the order of their ID numbers. If they are connected bya LAN circuit, all the devices can be checked simultaneously.

[0116] If the answer in Step 1 or Step 2 is “yes”, the control unit foreach device starts up its main program to render it operable (Step 3).If the answer is “no” in Steps 1 and 2, each control device executesprocessing to halt operation and control device 2 outputs an audiowarning (Step 4).

[0117] In the embodiments described above, when it is determined thatthere is no detection unit in any of the devices, the operation of eachdevice is interrupted. Alternatively, the devices themselves may beallowed to operate while only the input or output of image data ishalted.

[0118] In the embodiments discussed above, we assumed that the documentreproduction system consisted of image scanner 1, control device 2 andprinter 3. This invention, however, is not limited to the aforesaidsystem only. It could be applied in any system consisting ofinterconnected devices to input, output and process image data.

[0119] For example, a storage device such as a hard disk, a floppy diskor a CD driver can be connected to two or more control devices. If anyof these storage or control devices has a pattern detection unit andsomeone tries to make a copy of a storage medium on which image data arestored, any image data marked with the specified pattern can beprevented from being copied.

[0120] If there is a detection unit in one of the devices in a system inwhich a modem is connected to a control device to transmit image dataread by a scanner, it will not be possible to transmit image datarepresenting specified documents.

[0121] This invention, then, can be applied in any commonly usedcomputer system, where it will simply and reliably prevent thereproduction of image data associated with specified documents.

[0122] In some embodiments of the present invention, the patterndetection processing is executed on color image data synthesized bysuccessively combining image data for each color signal. In this way theoutput of specified color image data can be controlled.

[0123] In other embodiments of the present invention, if the function ofdetecting the pattern or controlling the data output is absent, thesystem is partially or completely halted. This will make it impossibleto output the image data of specified documents even if the deviceproviding the pattern detection or control function is removed from thesystem.

What is claimed is:
 1. An image processing method to process a colorimage data having a plurality of color signals which are inputsuccessively, comprising the steps of: storing said plurality of colorsignals except a last color signal separately in line memories;extracting a specified pattern from a restored color image combiningsaid plurality of color signals when said last color signal is input;matching said specified pattern against a reference pattern to obtain amatching result; and controlling an output of said color image datadepending on said matching result.
 2. An image processing method toprocess a color image data having a plurality of color signals which areinput successively, comprising the steps of: storing said plurality ofcolor signals separately in line memories; extracting specified patternsfrom said plurality of stored color signals individually; matching saidspecified pattern against a reference pattern to obtain a matchingresult; and controlling an output of said color image data depending onsaid matching result.
 3. An image processing method to process a colorimage data having a plurality of color signals which are inputsuccessively, comprising the steps of: verifying that a device detectingif a specified pattern exists in said color image data matches areference pattern and a device controlling the output of said colorimage data based on said detection exist in said system; and haltingsaid system if either device does not exist in said system.
 4. An imageprocessing system to process an image data having an image datageneration device to input an image data from a 2-dimensional object, acontrol device to process said image data from said image datageneration device, and an image data output device to output saidprocessed image data from said control device, comprising: a patterndetection device to detect if a specified pattern in said image datamatches a reference pattern, and a system control device to control theoutput of said image data depending on said matching.
 5. An imageprocessing system according to claim 4 , wherein said control deviceoutputs an altered image data based on said matching.
 6. An imageprocessing system according to claim 4 , wherein said control devicehalts the operation of said image processing system based on saidmatching.
 7. An image processing system according to claim 4 , whereinsaid pattern detection device comprises: a plurality of line memoriesfor separately storing a plurality of color signals except a last colorsignal; a pattern extraction unit to extract a specified pattern from arestored color image combining said plurality of color signals when saidlast color signal is input; a pattern matching unit to match saidspecified pattern against a reference pattern and obtain a matchingresult; and a selector unit to control an output of said image databased on said matching result.
 8. An image processing system accordingto claim 4 , wherein said pattern detection device comprises: aplurality of line memories for separately storing a plurality of colorsignals; a pattern extraction unit to extract specified patterns fromsaid plurality of stored color signals individually; a pattern matchingunit to match said specified patterns against a reference pattern andobtain a matching result; and a selector unit to control the output ofsaid image data based on said matching result.
 9. An image processingsystem to process an image data having an image data generation deviceto input an image data from a 2-dimensional object, a control device toprocess said image data from said image data generation device, and animage data output device to output said processed image data from saidcontrol device, comprising: a first verifying unit to verify there is apattern detection device in said system which detects if a specifiedpattern in said image data matches a reference pattern; a secondverifying unit to verify there is a system control device in said systemwhich controls the output of said color image data based on saidmatching; and a system halting unit to halt said system partially orcompletely if said first verifying unit determines there is no saidpattern detection device or said second verifying device determinesthere is no said system control device.
 10. An image data generationdevice to input an image data from a 2-dimensional object, comprising: apattern detection device to detect if a specified pattern in said imagedata matches a reference pattern, and a system control device to controlthe output of said image data based on said detection; wherein saidimage data is combined with a plurality of color signals which are inputsuccessively, and said pattern detection device is comprising: aplurality of line memories for seperately storing a plurality of colorsignals except a last color signal; a pattern extraction unit to extracta specified pattern from a restored color image combining said pluralityof color signals when said last color signal is input; a patternmatching unit to match said specified pattern against a referencepattern and obtain a matching result; and a selector unit to control theoutput of said image data based on said matching result.
 11. An imagedata generation device to input an image data from a 2-dimensionalobject, comprising: a pattern detection device to detect if a specifiedpattern said image data matches a reference pattern, and a systemcontrol device to control the output of said image data based on saiddetection; wherein said image data is combined with a plurality of colorsignals which are input successively, and said pattern detection devicecomprises: a plurality of line memories for seperately storing saidplurality of color signals; a pattern extraction unit to extract aspecified pattern from a color image of said plurality of color signalsindividually; a pattern matching unit to match said specified patternagainst a reference pattern and obtain a matching result; and a selectorunit to controll the output if said image data based on said matchingresult.
 12. An image data generation device to input an image data froma 2-dimensional object, comprising: a first verifying unit to verifythere is a pattern detection device in said system which detects if aspecified pattern in said image data matches a reference pattern; asecond verifying unit to verify there is a system control device in saidsystem which controls the output of said color image data based on saidmatching; and a system halting unit to halt said system partially orcompletely if said first verifying unit determines there is no saidpattern detection device or said second verifying device determinesthere is no said system control device.
 13. A control device to processsaid image data from said image data generation device, comprising: apattern detection device to detect if a specified pattern in said imagedata matches a reference pattern, and a system control device to controlthe output of said image data based on said detection; wherein saidimage data is combined with a plurality of color signals which are inputsuccessively, and said pattern detection device is comprising: aplurality of line memories for seperately storing a plurality of colorsignals except a last color signal; a pattern extraction unit to extracta specified pattern from a restored color image combining said pluralityof color signals when said last color signal is input; a patternmatching unit to match said specified pattern against a referencepattern and obtain a matching result; and a selector unit to control theoutput of said image data based on said matching result.
 14. A controldevice to process said image data from said image data generationdevice, comprising: a pattern detection device to detect if a specifiedpattern said image data matches a reference pattern, and a systemcontrol device to control the output of said image data based on saiddetection; wherein said image data is combined with a plurality of colorsignals which are input successively, and said pattern detection devicecomprises: a plurality of line memories for seperately storing saidplurality of color signals; a pattern extraction unit to extract aspecified pattern from a color image of said plurality of color signalsindividually; a pattern matching unit to match said specified patternagainst a reference pattern and obtain a matching result; and a selectorunit to controll the output if said image data based on said matchingresult.
 15. A control device to process said image data from said imagedata generation device, comprising: a first verifying unit to verifythere is a pattern detection device in said system which detects if aspecified pattern in said image data matches a reference pattern; asecond verifying unit to verify there is a system control device in saidsystem which controls the output of said color image data based on saidmatching; and a system halting unit to halt said system partially orcompletely if said first verifying unit determines there is no saidpattern detection device or said second verifying device determinesthere is no said system control device.
 16. An image data output deviceto output said processed image data from said control device,comprising: a pattern detection device to detect if a specified patternin said image data matches a reference pattern, and a system controldevice to control the output of said image data based on said detection;wherein said image data is combined with a plurality of color signalswhich are input successively, and said pattern detection device iscomprising: a plurality of line memories for separately storing aplurality of color signals except a last color signal; a patternextraction unit to extract a specified pattern from a restored colorimage combining said plurality of color signals when said last colorsignal is input; a pattern matching unit to match said specified patternagainst a reference pattern and obtain a matching result; and a selectorunit to control the output of said image data based on said matchingresult.
 17. An image data output device to output said processed imagedata from said control device, comprising: a pattern detection device todetect if a specified pattern said image data matches a referencepattern, and a system control device to control the output of said imagedata based on said detection; wherein said image data is combined with aplurality of color signals which are input successively, and saidpattern detection device comprises: a plurality of line memories forseperately storing said plurality of color signals; a pattern extractionunit to extract a specified pattern from a color image of said pluralityof color signals individually; a pattern matching unit to match saidspecified pattern against a reference pattern and obtain a matchingresult; and a selector unit to controll the output if said image databased on said matching result.
 18. An image data output device to outputsaid processed image data from said control device, comprising: a firstverifying unit to verify there is a pattern detection device in saidsystem which detects if a specified pattern in said image data matches areference pattern; a second verifying unit to verify there is a systemcontrol device in said system which controls the output of said colorimage data based on said matching; and a system halting unit to haltsaid system partially or completely if said first verifying unitdetermines there is no said pattern detection device or said secondverifying device determines there is no said system control device.